The 500 series was introduced in 1949 and made by the Bell System
until 1986. Its design was licensed to ITT in 1951 and other
manufacturers during the 50s, until it became the standard. It
continues to be made overseas to this day!
With the later addition of TouchTone, it evolved into the 1500
(10-button keypad), 2500 (12-button keypad), and 3500 (16-button
Autovon
military keypad) with similar model numbers.

500-type

Rotary

1500-type
10-button dial

2500-type
12-button dial

3500-type
16-button dial

Over the years, numerous
variations were made with
extra switches,
knobs and internal components for special purposes. Model numbers well above the 5xx range were
ultimately used. Western catalogs and technical documentation
only show the models that were in production or service at the
publication date. To understand the full scope of models produced
we must compile data from many years of documents.

This page was created as a casual attempt to answer the
simple
question,

"How many 500-series models did
Western
Electric make?"

The
question was first posed to Antique Telephone
Collectors
Association (ATCA) and Telephone Collectors International (TCI)
members, and other dealers and collectors in early 1997.
Following are the results to date (no claims are made
as to
accuracy or completeness).

~~ How
to use this page ~~

>> Table Organization:Sorted by
model
number for the rotary variations.>> Use: Search (usually Control-F in most
browsers) for
the last 3 digits
of the model number of your set. Or
Browse by
category, using the links above.

Note:
the Control-F search only works for models on this page. For
Touch Tone models, use the links above to go to the appropriate page,
then search.

Find the model number of your phone on the
bottom plate.In this case, look up 500C or 500D.
(This base code was shared by both models.)
More on model numbers here.Vermillion ink or other codes stamped on the bottom
may
indicate that
the phone was refurbished.
Watch for changed parts.

Manual
Sets (sets without dials) had an "apparatus blank" filling the
hole in the housing normally occupied by a dial.

Looking up the model number for your set should give you a brief
description of the major features of the model, and a BSP (Bell System
Practices) reference for the rotary set, if known. When
available, photos of some unique features are shown near the model
number or linked from the chart
entry. If you don't find your model listed, try looking up the
last 3 digits in the tables for other Western Electric models.
Often the major features were consistent among rotary and Touch Tone
models.

The BSPs
provide technical details and usually a wiring diagram. BSPs are
often found in the Station Service Manuals, Key Systems Service Manuals
and Station Specialties Service Manuals published in the 1970s and
early 80s. BSPs or wiring diagrams for some common models are
available on several
internet sites including the ATCA and TCI club sites. Several
club members have scanned some popular BSPs and make them available on
CD.
For more details on BSPs, click here.

You still
need to check the internal components as many phones
were
refurbed and had internal components changed or removed. For
example,
many phones marked 501D were converted from party line to single line
(500D) by removing the 426A tube as party lines lost favor. If
done in a Bell System refurb facility, the code on the bottom was
usually
repainted or remarked. Many independent shops or field mods were
not remarked with the accurate model number.

Check out
the table key
for model
numbering background and other reference details.

Note: There were no seperate model numbers for manual and dial versions.

Replaced
by the 500A and 500B -- often the A/B was added to the
existing 500 marking during refurb.

-

C38.595.1

Issue 1: 10/58

500 A
500 B

Early single line w/ 425A net & amp;
separate 311A equalizer. Model and date moved to a location near
the ringer, near where the word “LOUD” was stamped. See Photo.

Note: Bases were marked 500 A/B. This is a manufacturing code,
not the model number. See the table key for
details.

Replaced by the 500C
and 500D.

2,4,7,8,9

C38.595.1
C38.601

Issue 1: 10/58

502-501-101
502-510-400
502-521-401

500 C
500 D

Later single line w/ 425 B or E net and
varistors for equalization. (No separate equalizer needed.)

Replaced the 500A, 500B, 500J and 500K sets.

This is by
far the most popular variation and was made for decades.

2,4,7,8,9

C38.603
502-501-101
502-510-401

502-521-402

500 E
500 F

Single line w/
plunger switch to avoid
interference on extensions (or party lines). Lifting the left plunger
activates talk and dial circuits. Cradle is marked, “LIFT
PLUNGER TO DIAL OR TALK”. Replacing the handset resets the
switches. Replaces the 302AA/AC.See photos.

2,3,4,7,8,9

C32.535
C38.595.1

Issue 1: 10/58

502-501-115
502-510-402
502-580-402

500 H

Single line w/ hooded dial lamp (GE46 bulb,
6-8v ac or dc supply, P17A120 lamp cap assembly [contact me if you have
spares of this part!]), 425B network (or later 425E). The light
is only activated
when the handset is offhook.

Cannot be used as the tip party on message rate, automatic
ticketing, automatic message accounting or zone restriction
services. Replaced by the 500P and U for these services.Announced in 1954.

Single line w/ A-lead
control for 1A2.
4-conductor mounting cord and terminal strip installed below
dial. Originally used in applications where the ringer circuit
had to be brought out through the mounting cord.

2,7,8,9

C32.537
C38.595.1
C38.610

Issue 1: 10/58

502-501-115
502-510-405
502-580-405

500 P

Single line w/ hooded dial lamp (GE46 bulb,
6-8v ac or dc supply, P17A120 lamp cap assembly [contact me if you have
spares of this part!]), 425B network (or later 425E). The light
is only activated
when the handset is offhook.

Replaced the 500H to overcome limitations of that
set. Compatible
with all services supported by the 500D.

(Available in 1955,
MD ca. 1960)

2,3,4,7,8,9

C32.535
C32.537
C38.595.00
C38.595.1
C38.611

Issue 1: 10/58

502-501-115
502-510-406
502-510-410
502-580-406

500 R
500 S

Single line for
speakerphones, including the
1A, 1A1, 3A and 4A.
10-conductor
mounting cord, internal terminal strip, extra dial and switchhook
contacts
and separate ringer leads for speakerphone control. See
photos
(scroll to bottom of page.)

1,2,7,8,9

C38.595.1
C38.612

Issue 1: 10/58

502-501-115
502-580-408

500 T

Early single line w/ 425A net, no equalizer,
but terminal block for handset leads.

Use was limited to zones distant from the Central Office, where the
attenuating characteristics of the equalizer in the 500 set was not
needed. This was a cost saving measure.

Note: There were no seperate model numbers
for manual and dial versions.

Single line w/ hooded
dial lamp (GE46 bulb,
6-8v ac or dc supply, P17A120 lamp cap assembly [contact me if you have
spares of this part!]). 425B network (or later 425E). Similar to
the 500P with the addition of a night light
switch (584A key).

When switched
on, the night light glows dimly when handset is on hook and a full
brilliance when off hook. See Photo.
(MD 1963)

2,4,7,9

C32.535
C32.537
C38.595.00
C38.595.1
Issue 1: 10/58

C38.613
502-501-115
502-510-408
502-580-409

500 W
500 Y

Photo from Russ Cowell

Single line w/ neon
ringing/message waiting
lamp for PBX. Available in 1958.

1,2,4,7,8,9

C38.614
502-501-115

502-580-411

500 AB

Single line for
2-wire or 4-wire circuits
(no
speakerphone). Comes wired for 2-wire service butmay be converted
at installation to 4-wire service. Arranged for but not equipped
with a KS-8109L2 Buzzer. Intended for use in 1A1 and 1A2 Key
Telephone Systems and 3B Speakerphone Systems, however it is intended
for specially engineered lines. Not for general telephone use.For
touchtone model, see 2504 in "Other
Variations"
below.

6

502-510-411

500 AD

Single line for
4-wire circuits and 3-type
speakerphones. Arranged for 4-wire service and equipped with a
switch hook arrangement which provides one spare transfer and two spare
make contacts. The spare make contacts may be used for such
purposes as controlling external relays or applying idle line circuit
terminations. Arranged for but not equipped with a KS-8109L2
Buzzer. Intended for
use in 1A1 and 1A2 Key Telephone Systems and 3B Speakerphone Systems.For
touchtone model, see 2504 in "Other
Variations"
below.

2,3,7,8,9

502-501-115
502-512-101
502-512-401

502-580-401

GA-51859

TA236/FT

Single line with
Military markings on case:
Signal Corps US Army, Telephone Set TA236/FT,Western Electric.
(No Bell System markings.)

Earliest 501 A/B sets were not marked with
suffix codes. 501 and date were stamped in ink, usually along the front
edge of the baseplate. w/ separate equalizer. First production used C3A
ringer, then C4A.

Replaced
by the 501A and 501B -- often the A/B was added to the
existing 501 marking during refurb.

-

C38.595.1

Issue 1: 10/58

501 A
501 B

Early party line w/ separate equalizer.

Replaced
by the 500C and 500D.

1,2,8,9

502-510-400
502-521-404

501 C
501 D

Later party line w/ varistors for
equalization.

Replaced
the 501A, 501B, 501J and 501K sets.

2,8,9

C38.603
502-521-405
502-510-401

501 F

Party line w/ plunger
switch to connect talk
and dial circuits - to avoid interference with talking party.
Replaces the 306G.See photos.

2,7,8,9

C32.535
502-501-115
502-510-402

502-580-403

500 H
with tube

Early party line with
dial lamp
set. Created from a 500H by adding the 426A tube. (For some
reason apparently not marked 501H.)

Single line w/ hooded dial lamp (GE46 bulb,
6-8v ac or dc supply, P17A120 lamp cap assembly [contact me if you have
spares of this part!]), 425B network (or later 425E). The light
is only activated
when the handset is offhook.

Cannot be
used as the tip party on message rate, automatic
ticketing, automatic message accounting or zone restriction
services. Replaced by the 501P for these services.

C38.607
C38.621

501 J
501 K

Party line w/ 425A net w/o equalizer.

Replaced the 501T. Many 501T sets were remarked 501 J/K during
refurb.

Replaced
by the 501 C and 501D.

2,3,8,9

C38.609
502-521-406

501 P

Party line w/ dial lamp.

Replaced
the 500H with tube.

2,4,7,8,9

C38.611
502-501-115

502-510-406
502-580-407

501 T

Early Party line w/ 425A net, no equalizer,
but terminal block for handset leads.

Use was
limited to zones distant from the Central Office, where the
attenuating characteristics of the equalizer in the 501 set was not
needed. This was a cost saving measure.

OTHER
ROTARY VARIATIONSWE
532

(Pulling up on the exclusion plunger [white] operates a switch which
can be used for several functions, including cutting off other
extensions on the line for privacy.)

2,4,8,9

C32.540

C38.595.02
C38.628
502-515-100

502-515-400
502-531-401

503 B
503 C

Data

Single line used with Data-Phone equipment, with
exclusion key.

1

C38.595.02
C38.620
502-501-120
503-516-100
503-516-401

2504
- - -
3504

2- or 4-wire service

The 2504 is equipped with a line
switch which provides six transfer contacts and is arranged for
two-wire service. The set is convertible to four-wire service at
installation. 35C3B TOUCH-TONE Dial, N1A Ringer, 425G Network,
exclusion switch assembly operated by lifting the left plunger,
card-operated line switch. The set is arranged for mounting a
KS-8109L1 Buzzer which is not furnished. Intended solely for
specially engineered lines. Not for general telephone use.

The ringer
adjustment is on the left side along the bottom edge -- just
behind the handset cord hole.

The 3504
is for the AUTOVON network. Factory wired for 4-wire
service. 66A3A 16-button dial, N1A Ringer, 425G Network,460A
diode (polarity guard), 425D diode (surge protector), exclusion switch,
G3AR handset. The set is arranged for mounting a KS-8109L1 Buzzer
which is not
furnished. Intended solely for specially engineered lines. Not
for
general telephone use.

Also used on early
PBX systems with the
switch wired to provide “ground start” during power failures.

2,8,9

C38.595

C38.595.02
C38.628
502-515-100
502-515-400
502-531-402
C38.595

511 A
511 B

Two line

w/ extension set exclusion and
signal key

2,4,8,9

C38.595

C38.595.02
C38.628
502-515-100
502-515-400
502-531-403
C38.595

511 C
511 D

Two line

w/ extension set exclusion, signal
key and speakerphone

2,8,9

C38.595

C38.595.02
C38.628
502-515-100
502-515-400
502-531-404

511 F

Two line

w/ extension set exclusion,
speakerphone and A-lead control for 1A2, spade tip cord

2,8,9

500-124-180
502-531-405

511 H

Two line

w/ extension set exclusion,
speakerphone and A-lead control for 1A2, D50 connector

2,8,9

502-515-100
502-531-405

511 X30A

Voice Coupling using
30A Voice Coupler.

Provides 2-wire connection of customer-provided voice transmitting
and/or receiving equipment to Bell lines, DC isolation and
limits excessive line signal. Has a standard ¼” phone plug on
the right side. Connection is made by operating the exclusion key.

Single line with headset jack in back and
headset
mode/recall switch above right of dial. Ringer loudness control
on left side behind handset cord cutout.Message
waiting lamp optional with D-17998 kit of
parts.

Single line w/ receiver amplification and
push-to-listen button (G2 or G5 handset). It
provides limited receiver amplification and limited reduction of
transmitter and sidetone levels with the handset push-to-listen button
normal.

Designed for the small hotel/motel market, used in the guest
rooms. Control buttons and "A-leads" (control leads) tell the
switching equipment what kind of line to connect to the set (switching
done within the PBX).

4 buttons marked "Message waiting" (the front
desk could illuminate it to alert you to
a message), "Desk" (connected you to the front desk), "Local"
(connected you to a CO trunk for a local call), and "Long distance"
(gave you a direct path to a toll operator). Only 3 of the 4
buttons depressed. These button features relieved the
attendant
of having to route much of the guest traffic.

Outwardly, these sets look like
a 544 or 545 set but have fewer line cord conductors (12).

HB has round
buttons on the key strip and metal fingerwheel.
HF replaced HB
and has H1A ringer.
HR replaced the HF and has N1A ringer with
side-mounted volume control and case markings for LOUD and OFF, and a
clear fingerwheel.

Room for optional AC or DC operated
buzzer.
Available in black, red and white.

Many bases are marked
on the bottom 5nn x/y (e.g. 500
C/D).
This was a manufacturing convenience used where the same base component
was used to build several different variations and is not the model
number. Usually x=manual version (no
dial) and y=with dial. Model number 500C has an apparatus blank
instead of a
dial. Model number 500D has a dial.

There
are exceptions. The 500 P/U
base was used to make the 500P or 500U sets, both of which have
dials. Some bases are marked 500 P, some 500 U and some 500 P/U.

• Many TouchTone models have similar numbers, with a prefix of
1,
2
or 3, e.g. 15nn x/y.
(See the appropriate site page for touch tone models. Links
at the top of this page.)

1M or 2M suffix indicated bases that were inventoried as components,
separately from the color parts such as the housing and handset.
This was done to economize on the size and weight of sets carried in
the installers' trucks.
e.g. 500D2M - Modular 500 base

Planned daily installations were stocked in the truck as fully
assembled sets (e.g. 500DM). The installer could assemble a set
of the proper color for an extra extension added to the order while on
site using a 500D2M plus color kit plus cords. More info in BSP
503-100-100.

Color code is rarely
marked on sets. For a short time in the 1950s, when color was
new, dials and occasionally bases had a color code. More often
found in catalogs and on the boxes. (See photo of 500UR-59 above.)

*

Set wired for 1A1
or 1A2,
(typically found on 500L/M or keysets),
e.g. 500M*

Note: date codes on the right two phones are in the form YYDDD, where
YY is the last 2 digits of the year and DDD is the numeric day of the
year (001-365). Their bases are cad plated, rather than the
original black.

Date codes changed format in about 1978 for 500-type sets and in about
1977 for Princess sets.

•
COMPONENT EVOLUTION: Model numbers relate to "function" while
components in each
model changed from time to time, and were often phased gradually
into production. For example, in the 500D:

Western
Electric bakelite and soft
plastic receiver caps generally have 6
holes in a circle, and transmitter caps have three concentric circles
of 6, 12 and 18 holes, for a total of 36. Hard plastic caps each
have the same pattern with the addition of one hole
in the center of the pattern. Note that caps were often changed
in refurb, so are not a reliable indicator of handset plastic
material. For example, soft plastic caps are often found on
bakelite handles marked G1.

Handsets
and
bottom plates marked
"Bell System Property, Not for Sale" (1968-1983).

* Changes with Colored Sets starting in
1953: 7C dial, clear
hookswitch plungers, clear plastic fingerwheel. Look for color
code on the back of the 7C dials, e.g. 7C-59. Clear plastic
fingerwheels were also used on black 500H, P and U sets.

(Many individual
components have date
codes. It is not
uncommon to find refurbished phones with internal components of mixed
dates, as the Bell System was a master of recycling. I have
several sets with 2 leather feet and 2 plastic feet thanks to the
refurb shop. The real treasure is to find an early set
where all the dates match!)

• WE also made specials
for large customers
(e.g.
Howard Johnson).

•
Exclusion keys were wired for many purposes, including
ringer
cut-off, extension station cutoff, etc.

It's time for some
detective work. Fortunately, Western Electric left a lot of clues
for us to follow. Most components of the 500-series sets had both
model numbers and dates. This was important for them, as the Bell
System owned the phones at the time, and refurbished the sets to extend
their useful lifetime. Most of the sets we find today were in
service for many years and were probably refurbished at least
once. Original components were replaced with the currently
manufactured parts. Therefore, internal dates of the components
do not always match.

The dates
that are the most important in establishing age are the date
on the bottom plate and the date on the network. These two
components were usually joined in the assembly process using rivets, so
were difficult to change in refurb. If the dates match, that was
most probably the assembly date of the phone. Other
components used in the assembly would originally have had the
same month code or perhaps a date a month or two earlier.

Look at
the model number and date information carefully, to make sure
it hasn't been changed. Often, original dates have been painted
over and new dates stamped .

Original
date.
Set is a 500C (no dial)
(Vermillion code indicates
set was refurbished.)

Original
numbers
painted
out

New code in vermillion ink.

Original
code
painted out

New code in silver ink.
"CONV" = converted

Only
model variation
painted out
Date not changed!
Look for replaced parts.

Parts such
as the dial, ringer, cords, plastic housing and all handset
components usually also have dates. These parts are real easy to
change, so were often replaced during the phone's useful lifetime.

If your
phone has mixed dates, the interesting dates for it are
the dates on the base and network, and the dates of the last refurb or
newest component found.

Another
exercise for the phone sleuth is to try to determine what the
original model number was, if the original model number had been
painted over. Occasionally careful examination of the black paint
will show a slight raised pattern caused by the original ink
below. In other cases, remains of the previous model will be left
in place. For example, looking inside the phone from the
rightmost photo above revealed a terminal strip near the handset entry
hole. Therefore the original set was probably a 500T,
500J or 500K.
The original 425A
network had been removed and replaced with a 425B. The terminal
strip was left in place.

Phones stamped "CONV" usually had the network replaced. The
conversion was from the 425A to 425B.

COLORS:

Now that
you know how many models you need to collect, try
finding
them in all the following colors, by year!!

The color
code was appended to the model number as a
suffix.
Dates offered are included, where known. To view 1983 Western
Electric
Color Charts, follow these links:
For Phones , or
For Components . (Thanks to Todd Bernstein and David Massey
for providing these charts!)

Keychains
in "original" colors

WE 500 Colors: 1949 thru 1983

Note:
The first color
name
is typically the one found in the initial BSPs. Other names were
used in marketing literature and often differed among the Operating
Companies.

Note: Dates are based on first appearance in marketing literature. Sets
may be found dated the previous year.-3 Black
-29 Transparent (dates
unknown)

Government Agencies for Security Reasons -
To
listen or talk it is necessary to depress a button in the middle of the
handset.

These handsets are factory sealed units.

Models
include: G10A-F. G10A has two buttons on handle (receive
and transmit), G10E has one button controlling both functions.

501-210-301

G11

"Used with 15A, 15B
and 15C
apparatus which are part of 520A, 520B and 2520C explosion-proof
telephone sets.

Designed to provide protection against the
probability of explosion resulting from flames originating within the
handset under extreme conditions of operation." (Makes you wonder
about the rest of the handsets, doesn't it?) T3
transmitter, LA1
receiver, aluminum lined cavities.

501-210-102

G12

Early plug-in type
cord

Uses H4DB cord with Trimline-style plugs.

501-210-103

G13

photo from Jeremy Walters

Impaired Hearing -
for coin collector sets

Similar to G6B, except uses a slide switch instead of a potentiometer
and has an armored cord. Later handsets used two pushbuttons (as
shown). Switch provides either 10 or
20db gain and spring returns to normal position. Caps are
ultrasonically bonded to the handle, therefore components cannot be
replaced.

____________501-211-102
501-211-400

G15A

Basic handset with modular connection.

Replaced
G3 for modular applications.(Model
number is not marked on handset, just Bell System markings.)

501-210-103

G36

Long Route

Replaces original handset where
3db transmission gain or low current operation is required. (Only
works with rotary dials or touchtone dials equipped with a common
switch contact
arrangement to prevent dial sidetone amplification, and is polarity
sensitive.) When installed, a sticker was placed on the bottom of
the phone, "Equipped with G36 Handset", as there are no user controls
visible to indicate the presence of the amplifier.

501-211-103

G66

Impaired hearing

Receiver-amplifier unit
and polarity guard. Pushbutton provides an additional
10db gain in the receiver and 10 db loss in the transmitter
circuit. This handset is intended only for use by customers
who require more receiver gain than that provided by G6 type
handset. Recommended in place of the D-180413 handset.

501-211-102
Issue 6

GF

Handset for
5302.

Uses a
G1 or G3
handle, with adapters
for HA1 and F1 elements used in the F1 handset. See
photo

502-400-301 NY

732A

This is actually a
receiver that looks like
a G3
handset.

It has no transmitter element, the cup has no terminals
installed and the transmitter cap has no holes! Used on 691A subset.
(732A is in the coding series for receivers.) See
photo

502-200-101

KS-16504

High fidelity dynamic
microphone.

Used with
8A and 9A announcement systems (to record the message), or
as part of a high fidelity conference set.

501-210-120
501-210-300

J1

Control
of 1-type telephone
reporting set from a remote line. Similar to G5 with a switch
controlled oscillator for generating a 1475 cps signal.